Trainble or Dumwreck...

[Latino]

Hi guys!

I´m really glad I can join you through this forum.

I´ve been wondering:

Is there any realistic way to get the best of the two worlds (you know what I mean) in one blended beast? That would be one all mighty sonic weapon! Has it been done?

What are your thoughts about it?

[Darkbluemurder]

Latino,

That will be a real challenge because the topologies and the designs are quite different. The power tubes are different as well although EL 34 could be an acceptable common ground. The PI and negative feedback loops are vastly different. A substantial part of the Wrecks' sound is power amp distortion which is not as crucial in *umble's amps. IMHO this is also where amps with more than 2 channels have problems since a realistic crunch tone depends more on power amp compression/distortion than clean or high gain lead tones.

Finally the sound largely depends on the speakers used. 4x12'' seems to be standard with a Wreck whereas it is mostly 1x12'' or 2x12'' with a *umble.

A workable solution could be a D-style preamp for clean and overdrive on one side going directly to the power amp and a Wreck channel with a single ended 1W power amp on the other going also to the large power amp (this is what I believe the Guytron amp is doing - Vox pre- and power amp into a large power amp). The challenge would be to fit the single ended power amp to the large power amp. The system will be quite complex though.

Maybe some of the more experienced builders could chime in on this one.

[Harris]

I'm with Darkblue on this one. Not only are the topologies vastly different, but the tones of these amps are also completely different. The wreck is very raw, brown, and mean. The Dumble, by comparison is complex, compressed, and almost always has an underpinning of clean tone. You would be better off building two separate amps. I've built both and I don't see my Wreck getting much use now that I've built the Dumble...but that's my taste

[Normster]

I'm wrestling with the same design, but more Dumble-like than Trainwreck. I suspect that I'll end up with an amp that sounds like neither. As has been pointed out before, a major issue is that each breaks up differently so all I'm shooting for is to add some of the qualities of the Express to the Dumble sound.

The approach I'm considering is to model the first stage a bit closer to the Express to get more articulation. In a sense, it'll be more like the 70s ODS with 100k/1.5k, 22uF plate/cathode values. The tone stack may be a bit more of an issue but I'm leaning towards the Express since I do like the clean tone.

The first clipping stage would be Express-style that could be switchable to a second clipping stage ala Dumble. I'm not sure, but it might be possible to fatten things up on the Dumble side with a post-OD tone stack. I think there are also possibilities to integrate or switch the Express/ODS values using split plate loads.

For the power amp, I'm thinking of something along the lines of the Komet with a tube rectifier for a bit of sag. However, I really want to go with 6V6s for earlier breakup.

As I said, I really don't expect for the amp to sound like either the ODS or the Express, but I'd like some of the qualities of each amp to be present in the tone. I'm building it in an ODS chassis so I have lots of switching options. I'm also using Moose's TW trannys so I have a few options there as well with plate voltage and primaries.

Worst case is it'll sound like crap and I'll have to turn it into a 22 watt Dumble.

[Bob-I]

IMHO these 2 amps are conflicting designs that won't live in the same chassis well. The TW likes a clean preamp and a rude nasty power amp overdrive.... in a good way. The D likes a smooth creamy overdrive in the preamp with a clean polite power amp.

JMO

[Latino]

"Worst case is it'll sound like crap and I'll have to turn it into a 22 watt Dumble"

You know, I really like your aproximation about this. I don´t see that happening. Contrariwise, I´m eager to listen to some nice clips made with that beast.

Best of lucks with it!

John.

[ampdoc1]

I recently built an amp with the Trainwreck pre feeding a Cathode follower, to the relay and a Dumble non HRM OD section. It was pretty tasty all in all. Robert here in Kansas brought over his DClone and we played our guitars through both. It was immediately noticeable that my amp wasn't as smooth in either channel as the D, and I know from experience that it wasn't as "raw and untamed" as the Wrecks I've built. It wasn't bad, but it didn't do either as well as the (very close to) real things. Worth the time for the lesson though.

DEH

[Normster]

I recently built an amp with the Trainwreck pre feeding a Cathode follower, to the relay and a Dumble non HRM OD section. It was pretty tasty all in all. Robert here in Kansas brought over his DClone and we played our guitars through both. It was immediately noticeable that my amp wasn't as smooth in either channel as the D, and I know from experience that it wasn't as "raw and untamed" as the Wrecks I've built. It wasn't bad, but it didn't do either as well as the (very close to) real things. Worth the time for the lesson though.

DEH

Actually, that sounds a lot like what I'm shooting for...like a Dumble with attitude.

[Darkbluemurder]

I recently built an amp with the Trainwreck pre feeding a Cathode follower, to the relay and a Dumble non HRM OD section. It was pretty tasty all in all. Robert here in Kansas brought over his DClone and we played our guitars through both. It was immediately noticeable that my amp wasn't as smooth in either channel as the D, and I know from experience that it wasn't as "raw and untamed" as the Wrecks I've built. It wasn't bad, but it didn't do either as well as the (very close to) real things. Worth the time for the lesson though.

DEH

Actually, that sounds a lot like what I'm shooting for...like a Dumble with attitude.

Yeah, I will try to change the global presence pot in mine to a lead tone pot - 250kA with a 0.001 cap as dogears suggested and remove the snubber on OD 2 - that should give the D some attitude with the tone pot up and be smooth with the pot down.
I remember when I first tried my modded Concert (70s style) I accidentally forgot to put in the snubbers. I also did not have the negative feedback on CL 2 then. The sound was quite brutal but not in a bad way. Notes fed back more intensely in the highs. I'm not sure my band would have liked that though (he he).

[skyboltone]

Actually, that sounds a lot like what I'm shooting for...like a Dumble with attitude.

Maybe just a 100 watt Dumble with 500V on the plates. That ought to be pretty agressive sounding. Intermod will be in the neighborhood of 12-15%. And your neighborhood won't be happy at all.